The present invention relates to a quick connect/disconnect coupling arrangement for use in a handheld apparatus adapted to be employed for cleaning, waxing and/or polishing automobiles, vans, motor homes, airplanes, etc. For the purposes of convenience the apparatus will be referred to as a hand-held orbital polisher.
In a hand-held orbital polisher it is important that one polishing unit be readily removed and replaced by another so as to enable the machine to be used for different operations. It is also important that the change can be done quickly and that the coupling be capable of standing up to repeated changes.
A common type of coupling utilized includes a flat circular platen having a coaxial projection extending above the plate for driving connection to a vertical spindle and an annular plate member which includes a polishing pad and is secured to the platen by threaded fasteners. The spindle is offset to and driven by the vertical motor driven shaft of the machine, and unless the spindle is locked the platen is free wheeling.
It is known to provide interengaging lugs and lug receiving openings to couple a pair of plate members wherein the plate members are turned relative to one another so that the lugs of one plate member move behind a rear face of the other plate member to thereby prevent axial removal of the plate member relative to the flange.
This known type of coupling is quite effective but can have definite disadvantages. The coupling is designed relative to the direction of rotation of the shaft so that rotation tends to maintain the coupled relationship and the lugs are needed only to inhibit uncoupling. Unless the spacing of the lugs and ramps are very accurately formed, one or more of the ramps may be subject to a more severe wedging action so that a tight coupling is not possible. As a result, the connection may chatter and vibrate sufficiently to result in a poor finish on the surface and serious wear and damage within the machine. The high starting torque can cause the platen member to become so tightly wedged that when it is desired to change the polishing unit, it cannot be removed. Since the coupling is located between the polishing unit and the motor within the frame or housing of the machine, it is substantially impossible for the operator to apply the proper forces to the coupling to loosen it when it becomes wedged in this manner. Accordingly, a design utilizing interengaging lugs and ramps which obviates the above problems is described.